[kh99]

The OP has edited the file class_dm_threadpost.php and inserted the code in bold into the function verify_title() where shown (it still looks like it's around line 110). But you also need to use $this->info['forum']['forumid'] instead of $foruminfo['forumid'], so maybe like this:

	function verify_title(&$title)
	{
		// replace html-encoded spaces with actual spaces
		$title = preg_replace('/&#(0*32|x0*20);/', ' ', $title);

		if (in_array($this->info['forum']['forumid'], 1, 2, 3)) {
   		   $title = preg_replace('/[\.]/', ' ', $title);
		   $title = preg_replace('/[\-]/', ' - ', $title);
		   $title = str_replace("  ", " ", $title);
		}

		$title = trim($title);

Of course you'd replace 1, 2, 3 with the list of one or more forum ids where you want those characters removed.